Discuss as:

Smell of death at the scene of massacre in Syrian village, UN monitors say

Rebels in Syria say Assad's forces had slaughtered at least 78 people, including women and children, but Assad's people say it was the rebels and the numbers were far fewer. ITN's Paul Davies reports. Warning: Some pictures in this report are disturbing.

The smell of burned flesh hung in the air and body parts lay scattered around the deserted Syrian hamlet of Mazraat al-Qubeir on Friday, U.N. monitors said after visiting the site where 78 people were reported massacred two days ago.

The alleged killing spree on Wednesday underlined how little outside powers, divided and pursuing their own interests in the Middle East, have been able to do to stop increasing carnage in the 15-month-old uprising against President Bashar Assad.

A day after Syrian armed forces and villagers had turned them back, the unarmed U.N. monitors reached the farming settlement of Mazraat al-Qubeir, finding it deserted but bearing signs of deadly violence.

One house was damaged by rocket fire and bullets, U.N. spokeswoman Sausan Ghosheh said. Another was burned, with bodies still inside. "You could smell dead bodies and you could also see body parts in and around the village," Ghosheh told reporters after returning to Damascus.

Syrian troops shell rebel city as full-scale assault feared, activists say

BBC reporter Paul Danahar, who accompanied the U.N. monitors, said it was clear "terrible crime" had taken place.

In one house he saw "pieces of brains lying on the floor.

"There was a tablecloth covered in blood and flesh and someone had tried to mop the blood up by pushing it into the corner, but seems they had given up because there was so much of it around."

Blood was in pools around a room, Danahar tweeted. "Pieces of flesh lay among the scattered possession." Livestock carcasses were rotting in the sun.

The former U.N. secretary general, who brokered the peace deal that was to be implemented in Syria, has conceded that the plan is not working. Meanwhile, U.N. monitors attempting to investigate the latest massacre in Syria are facing gunfire. NBC's Ayman Mohyeldin reports.

Danahar's Twitter report added: "What we didn't find were any bodies of people. What we did find were tracks on the tarmac (that) the U.N. said looked like armored personnel carriers or tanks."

"Whoever did this may have acted with mindless violence but attempts to cover up the details of the atrocity are calculated & clear," Danahar concluded.

Ghosheh said Mazraat al-Qubeir, which has a population of around 150 people, was empty on Friday, but people from neighboring villages arrived to give their accounts.

Rebel fighter: Syria army firing on more villages after 'massacre'

"The information was a little bit conflicting. We need to go back, cross-reference what we have heard, and check the names they say were killed, check the names they say are missing."

Many Syrian civilians are fleeing their homes to escape widening fighting between security forces and rebels, the Red Cross said, while the outside world seems unable to craft an alternative to envoy Kofi Annan's failing peace plan.

"Some say that the plan may be dead," Annan said before meeting U.S. Secretary of State Hillary Clinton in Washington.

"Is the problem the plan or the problem is implementation?" he asked. "If it's implementation, how do we get action on that? And if it is the plan, what other options do we have?"

Activists say at least 78 people were shot, stabbed or burned alive in Mazraat al-Qubeir, a Sunni Muslim hamlet, by forces loyal to Assad, whose minority Alawite sect, an offshoot of Shi'ite Islam, has dominated Syria for decades.

Syrian authorities have condemned the killings in Mazraat al-Qubeir and another massacre of civilians in Houla two weeks ago, blaming them on "terrorists."

The conflict is becoming increasingly sectarian. Shabbiha militiamen from the Alawite community appear to be off the leash, targeting Sunni civilians almost regardless of their part in the uprising.

Opposition activists said those killed in Mazraat al-Qubeir had not previously been caught up in the conflict.

Reuters contributed to this report.

More world news from msnbc.com and NBC News:

Follow us on Twitter: @msnbc_world